This invention relates to a packaging apparatus for packaging a rolled article with light-shielding materials, and more particularly, relates to a packaging apparatus capable of preparing a package of a rolled article which is openable by extending a leading end of a light-shielding leader.
A package of a rolled article openable by extending a leading end of a light-shielding leader which is wrapped around the periphery of the rolled article is described in EP 0 414 265 A2.
In a package of a rolled article, as shown in FIGS. 7 and 8, the rolled article 1, such as a photographic photosensitive material, is wound around a hollow core 2 having almost the same width as the rolled article 1. A leading end of a light-shielding leader 3 having a width identical with or slightly greater than the rolled article 1 is connected with a leading end of the rolled article 1 so that the side edges B of the rolled article 1 almost conform with the side edges A of the light-shielding leader 3. Light-shielding covers 4, 4 are superposed onto each inner side edge of the light-shielding leader 3, and the superposed portions are heat-sealed. The outer edge C of the heat-sealed portion between the light-shielding leader 3 and the light-shielding cover 4 almost conforms with the side surface B of the rolled article 1, and it becomes a tear reinforcing portion when article 1 is opened.
The light-shielding leader 3 is wrapped around the rolled article 1, and the leading end is fixed to the rolled article 1 by adhesive tape 5. The light-shielding cover 4 is gusseted along the side surfaces of the rolled article 1, and the edges 8 are fixed by a pair of fixing members pressure fitted into the inside of the core 2.
A high density polyethylene film or the like having excellent heat sealability is used as the light-shielding leader 3, and a high density polyethylene film or the like having excellent tearability and heat sealability is used as the light-shielding cover 4.
In use, the package is loaded on a delivery shaft of an apparatus. The leading end of light-shielding leader 3 is extended from rolled article 1 and the light-shielding covers 4 are torn. The tears are guided by the heat-sealed portions and the tears proceed along the outer edges C. When the leading end of the rolled article 1 is extended, light-shielding leader 3 is peeled or cut off the rolled article 1. The rolled article 1 may then be used.
A conventional packaging apparatus for preparing a package of such a rolled article is disclosed in Japanese Patent KOKAI No. 58-2191. The gusseting mechanism of this apparatus, however, is complicated and increases the cost of the apparatus. Also, gusseting is conducted after wrapping the packaging material in this apparatus, and thus it is difficult to shorten cycle time.
A packaging apparatus which wraps and gussets was proposed in Japanese Patent KOKAI No. 58-134825. This packaging apparatus can gusset in a simple mechanism. Moreover, unless articles are large, wrapping gusseting speed is improved.
However, when using a packaging material resistant to creasing, such a polyethylene, it is difficult to convey the packaging material in a U-shaped form and it is difficult to maintain directional accuracy of the packaging material in a cross direction. Moreover, tucks formed by gusseting may break, and it is difficult to stably fix the light-shielding covers. Furthermore, a portion of the packaging material is used as a leader by making it longer than the edge of the light-shielding cover, it is necessary to attach the leader portion as a separate member or to employ a previous punching process, requiring additional equipment.
Thus, it will be appreciated that although various types of apparatus for packaging of a rolled article have been proposed, there is no apparatus for packaging a rolled article which uses a packaging material composed of a light-shielding leader and light-shielding cover adhered to each other.